Solution to the issue of high-order diffraction images for cylindrical computer-generated holograms.

The cylindrical computer-generated hologram (CCGH), featuring a 360° viewing zone, has garnered widespread attention. However, the issue of high-order diffraction images due to pixelated structure in CCGH has not been previously reported and solved. For a cylindrical model offering a 360° viewing zone in the horizontal direction, the high-order diffraction images always overlap with the reconstruction image, leading to quality degradation. Furthermore, the 4f system is commonly used to eliminate high-order diffraction images in planar CGH, but its implementation is predictably complex for a cylindrical model. In this paper, we propose a solution to the issue of high-order diffraction images for CCGH. We derive the cylindrical diffraction formula from the outer hologram surface to the inner object surface in the spectral domain, and based on this, we subsequently analyze the effects brought by the pixel structure and propose the high-order diffraction model. Based on the proposed high-order diffraction model, we use the gradient descent method to optimize CCGH accounting for all diffraction orders simultaneously. Furthermore, we discuss the issue of circular convolution due to the periodicity of the Fast Fourier Transform (FFT) in cylindrical diffraction. The correctness of the proposed high-order diffraction model and the effectiveness of the proposed optimization method are demonstrated by numerical simulation. To our knowledge, this is the first time that the issue of high-order diffraction images in CCGH has been proposed, and we believe our solution can offer valuable guidance to practitioners in the field.

Quality improvement of unfiltered holography by optimizing high diffraction orders with fill factor.

Computer-generated holography (CGH) suffers from high diffraction orders (HDOs) due to the pixelated nature of spatial light modulators (SLMs), typically requiring bulky optical filtering systems. To address this issue, a novel unfiltered holography approach known as the high-order gradient descent (HOGD) algorithm was previously introduced to optimize HDOs without optical filtering, enabling compact holographic displays. However, this algorithm overlooks a crucial physical parameter of SLMs-the fill factor-leading to limited optical quality. Here, we introduce a fill factor-based HOGD (FF-HOGD) algorithm, specifically designed to improve the quality of unfiltered holography by incorporating the fill factor into the optimization process. The quality advantage of FF-HOGD is demonstrated through numerical simulations and optical experiments.

Synthesis of surficial-modified green biochar catalyst generated by biogas residue biochar and potential application for catalytic ozonation degradation of ciprofloxacin.

This study synthesized novel, green, and easily recoverable surface-modified economical catalysts via hydrothermal treatment (HT) successfully, utilizing biogas residue biochar (BRB), a food waste product from anaerobic fermentation, pyrolyzed at 500 °C for 50 min. Using autoclaves, a total of six solutions were prepared, each having 1 g fine-grinded BRB, surficial modified by adding glycerol (GL) (10 or 20 mL) and SDI water (70 or 60 mL), and heated in an oven at 240 °C, 180 °C, and 120 °C for 24 h. Afterward, the catalysts showed the potential for degradation of widely used emerging pollutants like ciprofloxacin. Taking advantage of catalytic surface modification, the catalytic ozonation degradation was more effective than that of a single ozonation. However, under similar conditions, catalyst amount 0.20 g, ozone dose 15 mg L-1, and ciprofloxacin 80 mg L-1, the performance of the 10 mL GL-180 °C catalyst was excellent. It showed a 92.45%-94.41% optimum removal rate in the 8-10 min interval. After five continuous cycles, the 10 mL GL-180 °C catalyst exhibited excellent stability and reusability. XPS, FT-IR, BET, XRD, and SEM before and after the reaction confirmed the successful synthesis and degradation mechanism. A possible degradation pathway was unrevealed based on a liquid chromatography-mass spectrometer (LC-MS) and scavenger test, proving the significant roles of superoxide radicals (O2•-), hydroxyl radicals (•OH), and singlet oxygen (1O2). Further, Electron paramagnetic resonance (EPR) analysis confirmed the presence of active oxygen species. Subsequently, 10 mL GL-180 °C showed promising degradation for the actual water environment, such as groundwater (73.55%) and river water (64.74%). This work provides a valuable economic strategy to convert biogas residue biochar into a low-cost catalyst for organic pollutant decomposition.

Response of microbial communities to exogenous nitrate nitrogen input in black and odorous sediment.

Since nitrate nitrogen (NO3--N) input has proved an effective approach for the treatment of black and odorous river waterbody, it was controversial whether the total nitrogen concentration standard should be raised when the effluent from the sewage treatment plant is discharged into the polluted river. To reveal the effect of exogenous nitrate (NO3--N) on black odorous waterbody, sediments with different features from contaminated rivers were collected, and the changes of physical and chemical characteristics and microbial community structure in sediments before and after the addition of exogenous NO3--N were investigated. The results showed that after the input of NO3--N, reducing substances such as acid volatile sulfide (AVS) in the sediment decreased by 80 % on average, ferrous (Fe2+) decreased by 50 %, yet the changing trend of ammonia nitrogen (NH4+-N) in some sediment samples increased while others decreased. High-throughput sequencing results showed that the abundance of Thiobacillus at most sites increased significantly, becoming the dominant genus in the sediment, and the abundance of functional genes in the metabolome increased, such as soxA, soxX, soxY, soxZ. Network analysis showed that sediment microorganisms evolved from a single sulfur oxidation ecological function to diverse ecological functions, such as nitrogen cycle nirB, nirD, nirK, nosZ, and aerobic decomposition. In summary, inputting an appropriate amount of exogenous NO3--N is beneficial for restoring and maintaining the oxidation states of river sediment ecosystems.

Asymmetrical neural network for real-time and high-quality computer-generated holography.

Computer-generated holography based on neural network holds great promise as a real-time hologram generation method. However, existing neural network-based approaches prioritize lightweight networks to achieve real-time display, which limits their capacity for network fitting. Here, we propose an asymmetrical neural network with a non-end-to-end structure that enhances fitting capacity and delivers superior real-time display quality. The non-end-to-end structure decomposes the overall task into two sub-tasks: phase prediction and hologram encoding. The asymmetrical design tailors each sub-network to its specific sub-task using distinct basic net-layers rather than relying on similar net-layers. This method allows for a sub-network with strong feature extraction and inference capabilities to match the phase predictor, while another sub-network with efficient coding capability matches the hologram encoder. By matching network functions to tasks, our method enhances the overall network's fitting capacity while maintaining a lightweight architecture. Both numerical reconstructions and optical experiments validate the reliability and effectiveness of our proposed method.

The optimum particle size of anaerobic ammonia oxidation granular sludge under different substrate concentrations.

The nitrogen removal performance of anaerobic ammonia oxidation granular sludge (AnGS) varies widely among particle sizes. In this paper, the nitrogen removal performance, extracellular polymeric substances (EPS) secretion level and microbial community of AnGS with different particle sizes were investigated to select the optimal particle size for different substrate concentrations. The results showed that the optimal particle size migrated from 0.6-1.6 mm to 1.6-2.5 mm and then to 2.5-3.2 mm as the substrate concentration increased. When the influent concentration of NH4+-N was 110 mg/L, granular sludge with particle size of 1.6-2.5 mm showed excellent nitrogen removal performance with the highest EPS secretion, while the highest EPS secretion gradually migrated to smaller particles as the substrate concentration decreased. The nitrogen removal performance of AnGS with different particle sizes depends on different proportions of anaerobic ammonium-oxidizing (anammox) bacteria (Candidates_Jettenia, Candidates_Kuenenia, Candidatus_Brocadia), heterotrophic nitrification aerobic denitrifying bacteria (Acinetobacter) and denitrifying bacteria (Denitratisoma). The optimum particle size range for AnGS has been clarified for different influent nitrogen concentrations, which can provide some new understanding for the application of anammox reactors.

Association between left ventricular diastolic dysfunction and septic acute kidney injury in severe sepsis and septic shock: A multicenter retrospective study.

INTRODUCTION: Left ventricular diastolic dysfunction (LVDD) adversely impacts renal function, and E/e' is a significant predictor of adverse kidney events under different clinical conditions. However, no studies have evaluated the association between LVDD and septic acute kidney injury (AKI) among patients with severe sepsis and septic shock. METHODS: This multicenter retrospective study evaluated adult patients with severe sepsis or septic shock between January 1, 2013, and December 31, 2019, who underwent echocardiography within 24 hours after admission to an intensive care unit. RESULTS: A total of 495 adult patients were enrolled in the study. LVDD grades II and III were associated with severe (stage 3) AKI (p < 0.001, p for trend < 0.001). E/e' and e' were risk factors for septic AKI (OR, 1.155; 95% CI, 1.088-1.226, p < 0.001; and OR, 7.218; 95% CI, 2.942-17.712, p < 0.001, respectively) in the multivariate logistic regression analysis. The area under the receiver operating characteristic curve of E/e' and e' was 0.728 (95% CI, 0.680-0.777, p < 0.001) and 0.715 (95% CI, 0.665-0.764, p < 0.001), respectively. CONCLUSIONS: LVDD was associated with septic AKI, and E/e' and e' are useful predictors of septic AKI among patients with severe sepsis or septic shock. TRIAL REGISTRATION: The study was registered at the Chinese Clinical Trial Registry (Protocol No. ChiCTR2000033083).

Synthesis of an easily recyclable and safe adsorbent from sludge pyrochar for ciprofloxacin adsorption.

Utilization of sludge pyrochar (SP) is the terminal step to loop the entire harmless disposal process of sewage sludge with pyrolysis. A new, easily recyclable, and safe adsorbent with well-immobilized heavy metals (HMs) was prepared from SP for ciprofloxacin (CIP) adsorption. The operational conditions for the adsorbent preparation were systematically optimized based on recycling rate and adsorption performance. Additionally, the adsorption conditions, adsorption kinetics, isotherms, and regeneration of adsorbents were further investigated in the present study. The results showed that easily recyclable and safe adsorbents were successfully prepared at 1100 °C under N2 atmospheric conditions (SPA-N-1100) with a maximum CIP adsorption capacity of 10.42 mg/g. SPA-N-1100 exhibited good CIP adsorption performance at an adsorption temperature of 45 °C and pH between 8.0 and 9.0. The adsorbents were regenerated by thermal desorption at 450 °C with a thorough decomposition of CIP. The adsorption mechanism was mainly dominated by its special porous microspheres-accumulation structure and surface species (e.g., FeP and graphite). Moreover, HMs in the adsorbents were well immobilized in SPA-N-1100 by the generation of new metal mineral phases and encapsulation of melting minerals, which had an ultralow potential for ecological risk during application.

Effective adsorption of Direct Red 23 by sludge biochar-based adsorbent: adsorption kinetics, thermodynamics and mechanisms study.

Using solid adsorbents, such as biochar, has been a potential practice to remove the pollutants from water bodies to render the water safer for potential usage. A potential application of sludge biochar-based adsorbent (SBA), obtained by pyrolysis with hydrothermal treatment, was developed to adsorb Direct Red 23 (DR23) from wastewater. The results showed that for the synthesized SBA (0.5 g/L) in the adsorption of DR23 at low concentration (<20 mg/L), the DR23 was totally removed from the aqueous solution. pH had a limited effect on the adsorption, while an increase in temperature was shown to have a large enhancing effect. The adsorption kinetics were best fitted by the pseudo-second-order kinetic model, while the equilibrium data were best fitted by the Langmuir isotherm. A maximum saturation adsorption capacity of SBA of 111.98 mg/g was achieved. SBA could then be regenerated by pyrolysis, and after three cycles, SBA still retained good adsorption ability for DR23, a removal rate exceeding 97% was achieved. Functional groups, pores, π-π bond, and electrostatic interactions are the key to the adsorption mechanisms. The results proved that SBA would be a promising material in the application of removing dyes in printing and dyeing wastewater.

Mechanism of ammonium sharp increase during sediments odor control by calcium nitrate addition and an alternative control approach by subsurface injection.

Nitrate-driven sulfide/ferrous oxidation has been proved a cost-effective approach for river sediments in-situ odor control. However, calcium nitrate addition would sharply increase ammonium concentration in interstitial water and the mechanism was not yet clear. In this work, though sulfide and ferrous iron were efficiently oxidized, about 102% of NH4+ concentration increased in interstitial water on the first day of calcium nitrate injection (30 mg kg dwt-1), and about 31% more NH4+ increase at the 21st days was observed. To discover the mechanism of ammonium sharp release, desorption kinetics experiment was conducted and the results suggested that the short-time sharp releases of ammonium when calcium nitrate was added could be attributed to the chemical extraction of exchangeable ammonium by calcium ion. Furthermore, at the end of treatment, many genus such as Thiobacillus, Sulfurimonas, Thermomonas, and Clostridium, which were closely related to sulfide and ferrous-driven denitrification and dissimilatory nitrate reduction to ammonium (DNRA), were identified by 16S rRNA Illumina sequencing method. These findings indicated the long-time increase of ammonium might be determined by the biochemical processes (e.g. DNRA) driven by nitrate reduction. Therefore, to avoid the impact of ammonium release, an alternative subsurface injection method was introduced in this work, and the results showed that ammonium releases could be well controlled when the injection position was beneath 10 cm of the sediment surface.

Chemical speciation and distribution of potentially toxic elements in soilless cultivation of cucumber with sewage sludge biochar addition.

Potentially toxic elements in municipal sewage sludge can be effectively immobilized during biochar production via pyrolysis. However, the bioavailability of these elements when biochar is applied in soilless cultivation to improve substrate quality has yet to be sufficiently established. In this study, we investigated the chemical speciation and cucumber plant uptake of potentially toxic elements in soilless cultivation when the growth substrate was amended with sewage sludge biochar (0, 5, 10, 15, and 20 wt%). It was found that the addition of 10 wt% biochar was optimal with respect to obtaining a high cucumber biomass and achieving low environmental risk considering the occurrence of hormesis. When the substrate was amended with 10 wt% biochar, cucumber fruit contained lower concentrations of As, Cr, and Zn and smaller bioavailable fractions of As, Cd, Cr, Ni, Cu, and Zn compared with the fruit of control plants, thereby meeting national safety requirements (standard GB 2762-2012, China). Most of the As and Cd taken up by cucumbers accumulated in the leaves and fruit, whereas Cr was found primarily in the roots, and most Ni, Cu, and Zn was detected in the fruit. Importantly, only small proportions of the potentially toxic elements in biochar were taken up by cucumber plants (As: 0.0075%; Cd: 0.038%; Ni: 0.0064%; Cu: 0.0016%; and Zn: 0.0015%). Given that the As, Cd, Ni, and Zn speciation in sewage sludge biochar was effectively immobilized after cultivation, the findings of this study indicate that sewage sludge biochar is a suitable substrate amendment in terms of the risk posed by potentially toxic elements.

Effect of pyrolysis temperature on characteristics, chemical speciation and risk evaluation of heavy metals in biochar derived from textile dyeing sludge.

Textile dyeing sludge (TDS) was pyrolyzed at temperature ranging from 300 to 700 °C to investigate characteristics and to evaluate the risk of heavy metals (Zn, Cu, Cr, Ni, Cd, and Mn) in biochar derived from the TDS. The analyzation of characteristics and potential environmental risk evaluation of heavy metals were conducted by the BET-N2, FTIR, and BCR sequential extraction procedure. The results showed that the pyrolysis treatment of the TDS contributed to the improvement of the pH value and specific surface areas with increasing pyrolysis temperature. Conversion of the TDS to biochar significantly decreased the H/C and O/C ratios, resulting in a far stronger carbonization and a higher aromatic condensation for the TDS derived biochar. The total contents of Zn, Cu, Cr, Ni and Mn in biochar increased with pyrolysis temperature owing to the thermal decomposition of organic matter in the TDS; but for Cd, the portion distributed in the biochars decreased significantly when the temperature increased up to 600 °C. However, using BCR sequential extraction procedure and analysis, it was found that pyrolysis process promoted changes in the chemical speciation and biochar matrix characteristics, leading to reduce bio-available fractions of heavy metals in the biochars. The potential environmental risk of heavy metals decreased from considerable risk in the TDS to low risk or no risk in biochar after pyrolysis above 400 °C. This work demonstrated that the pyrolysis process was a promising method for disposing of the TDS with acceptable environment risk.

Index for nitrate dosage calculation on sediment odor control using nitrate-dependent ferrous and sulfide oxidation interactions.

Nitrate-driven sulfide and ferrous oxidation have received great concern in researches on sediments odor control with calcium nitrate addition. However, interrelations among sulfide oxidation, ferrous oxidation and their associated microbes during the nitrate reduction process are rarely reported. In this work, a nNO3/n(S+Fe) ratio (mole ratio of NO3- concentration to S2- and Fe2+ concentration) was first introduced as an index for calcium nitrate dosage calculation. Then certain amount of calcium nitrate was added to four sediment systems with various sulfide and ferrous initial concentration to create four gradients of nNO3/n(S+Fe) ratio (0.6, 0.9, 1.5 and 2.0) for treatment. Furthermore, the significant variations of sulfide and ferrous oxidation, microbial diversity and community structure were observed. The results revealed that at low nNO3/n(S+Fe) ratio (0.6 and 0.9) systems, sulfide seemed prior to ferrous to be oxidized and no obvious ferrous oxidation occurred. Meanwhile, sulfide oxidizing associated genus Sulfurimonas sp. became dominant in these systems. In contrast, sulfide and ferrous oxidation rate increased when nNO3/n(S+Fe) ratio reached 1.5 and 2.0 (two and three times of theoretically required amount for sulfide and ferrous oxidation), which made Thiobacillus sp. more dominant than Sulfurimonas sp. Hence, when nNO3/n(S+Fe) ratio of 1.5 and 2.0 were used, sulfide and ferrous could be simultaneously oxidized and no sulfide regeneration appeared in two months. These results demonstrated that for sulfide- and ferrous-rich sediment treatment, the nitrate consumed by ferrous oxidation should be taken into account when calculating the nitrate injecting dosage. Moreover, nNO3/n(S+Fe) ratio was feasible as a key parameter to control the oxidation process and as an index for calcium nitrate dosage calculation.

An alternative approach for nitrate and arsenic removal from wastewater via a nitrate-dependent ferrous oxidation process.

Owing to the high efficiency of converting nitrate to nitrogen gas with ferrous iron as the electron donor, the process of nitrate-dependent ferrous oxidation (NDFeO) has been considered suitable to treat wastewater that contains nitrate but lacks organic matter. Meanwhile, arsenic immobilization often has been found during the NDFeO reaction. Thus, it was strongly expected that nitrate and arsenic could be removed simultaneously in co-contaminated wastewater through the NDFeO process. However, in the current work, arsenic was not removed during the NDFeO process when the pH was high (above 8), though the nitrate reduction rate was over 90%. Meanwhile, the biosolid particles from the NDFeO process demonstrated strong adsorption ability for arsenic when the pH was below 6. Yet, the adsorption became weak when the pH was above 7. Fourier transform infrared (FTIR) spectroscopy analysis revealed that the main activated component for arsenic adsorption was iron oxide in these particles, which was easily crippled under high pH conditions. These results implied that co-removal of nitrate and arsenic in wastewater treatment using NDFeO was difficult to carry out under high pH conditions. Thus, a two-step approach in which nitrate was removed first by NDFeO followed by arsenic adsorption with NDFeO biosolids was more feasible.

Study of ciprofloxacin removal by biochar obtained from used tea leaves.

In this study, used tea leaves (UTLs) were pyrolyzed to obtain used tea-leaf biochar (UTC), and then the UTC was used as an adsorbent to remove ciprofloxacin (CIP) from aqueous solutions. Batch experiments were conducted to investigate the CIP adsorption performance and mechanism. The results showed that the CIP-adsorbing ability first increased and then declined as the UTC pyrolysis temperature increased. The UTC obtained at 450°C presented excellent CIP-absorbing ability at pH6 and 40°C. The maximum monolayer adsorption capacity was 238.10mg/g based on the Langmuir isotherm model. The pseudo-second-order kinetic equation agreed well with the CIP adsorption process, which was controlled by both external boundary layer diffusion and intra-particle diffusion. The characterization analysis revealed that the OH groups, CC bonds of aromatic rings, CH groups in aromatic rings and phenolic CO bonds play vital roles in the CIP adsorption process, and that the NC, NO, OCO and COH groups of UTC were consumed in large quantities. π-π interactions, hydrogen bonding and electrostatic attraction are inferred as the main adsorption mechanisms. The present work provides not only a feasible and promising approach for UTLs utilization but also a potential adsorbent material for removing high concentrations of CIP from aqueous solutions.

Temperature response of sulfide/ferrous oxidation and microbial community in anoxic sediments treated with calcium nitrate addition.

Nitrate-driven sulfide oxidation has been proved a cost-effective way to control sediments odor which has long been a universal problem for urban rivers in south China areas. In this work, sediments treatment experiments under a dynamic variation of temperature from 5 °C to 35 °C with 3% of calcium nitrate added were conducted to reveal the influence of temperature variation on this process. The results showed that microbial community was remarkably restructured by temperature variation. Pseudomonas (15.56-29.31%), Sulfurimonas (26.81%) and Thiobacillus (37.99%) were dominant genus at temperature of ≤15 °C, 25 °C and 35 °C, respectively. It seemed that species enrichment occurring at different temperature gradient resulted in the distinct variation of microbial community structure and diversity. Moreover, nitrate-driven sulfide and ferrous oxidation were proportionally promoted only when temperature increased above 15 °C. The dominant bacteria at high temperature stage were those genus that closely related to autotrophic nitrate-driven sulfide and ferrous oxidizing bacteria (e.g.Thiobacillus, Sulfurimonas and Thermomonas), revealing that promotion of sulfide/ferrous oxidation could be attributed to the change of dominant bacteria determined by temperature variation. Thus, a higher treatment efficiency by calcium nitrate addition for odor control would be achieved in summer than any other seasons in south China areas.

Biodegradation of sulfamethazine by an isolated thermophile-Geobacillus sp. S-07.

Sulfamethazine (SM2) is an antimicrobial drug that is frequently detected in manure compost, is difficult to degrade at high temperatures and is potentially threatening to the environment. In this study, a thermophilic bacterium was isolated from the activated sludge of an antibiotics pharmaceutical factory; this bacterium has the ability to degrade SM2 at 70 °C, which is higher than the traditional manure composting temperature. The strain S-07 is closely related to Geobacillus thermoleovorans based on its 16S rRNA gene sequence. The optimal conditions for the degradation of SM2 are 70 °C, pH 6.0, 50 rpm rotation speed and 50 mL of culture volume. More than 95% of the SM2 contained in media was removed via co-metabolism within 24 h, which was a much higher percentage than that of the type strain of G. thermoleovorans. The supernatant from the S-07 culture grown in SM2-containing media showed slightly attenuated antibacterial activity. In addition, strain S-07 was able to degrade other sulfonamides, including sulfadiazine, sulfamethoxazole and sulfamerazine. These results imply that strain S-07 might be a new auxiliary bacterial resource for the biodegradation of sulfonamide residue in manure composting.

Optimization of operating parameters of hybrid vertical down-flow constructed wetland systems for domestic sewerage treatment.

In this work, three hybrid vertical down-flow constructed wetland (HVDF-CW) systems with different compound substrates were fed with domestic sewage and their pollutants removal performance under different hydraulic loading and step-feeding ratio was investigated. The results showed that the hydraulic loading and step-feeding ratio were two crucial factors determining the removal efficiency of most pollutants, while substrate types only significantly affected the removal of COD and NH4(+)-N. Generally, the lower the hydraulic loading, the better removal efficiency of all contaminants, except for TN. By contrast, the increase of step-feeding ratio would slightly reduce the removal rate of ammonium and TP but obviously promoted the TN removal. Therefore, the optimal operation of this CWs could be achieved with low hydraulic loading combined with 50% of step-feeding ratio when TN removal is the priority, whereas medium or low hydraulic loading without step-feeding would be suitable when TN removal is not taken into consideration. The obtained results in this study can provide us with a guideline for design and optimization of hybrid vertical flow constructed wetland systems to improve the pollutants removal from domestic sewage.